Degree compass



lil

Patented Aug. 7, i923.

reussi unir s'rA'rEs PATENT oFri'cE.

" Ani-linen e. covniin, er1 concurra, MICHIGAN.`

DEGREE COMPASS.

Application led March 15, 1926. Serial No. 94,862.

This invention relates to precision instruments oiI the type known as protractor or degree compass, and the primary'obgelct o l this invention is to provide a device ot this character which may be used .with work ot varying sizes and diameters. .i 1

@ne et the primary objects et my invention is to provide a degree compass which has an extensible pointer, pivotally mounted at the center ot a disk which vis provided with means tor securing the same in any predetermined position. s

Another object ot the instant invention is te provide a novelly constructed mounting for the pivotally mounted pointer which serves to maintain the pointer in a proper working position and which also cooperates with its centering pin to maintain the compass in the centered location. l

15in even further object of the presentinvention is the provision of a degree compass which is equipped with adjustable brackets tor attaching the saine to work having a larger diameter than the degree disk thereot and which are also adapted to move the disk toward and away from the work.

Many minor objects of the invention and relineinents of construct-ion will appear during the course ot the detailed specification i referring to the accompanying drawing, in

which Figure 1 is a tace view of a degree com-` pass constructed 1n accordance with my 1n-4 vention.

Fig. 2 is a cross section through the saine taken along line lllll oitllig. 1, and,

Fig. 3 isan enlarged detailed view ofthe pointer extension aliiiiing means, taken on line lll-lll of Fig. 1. Y

ln the drawing, where similar reference numerals roter to like parts throughout the several views, the numeral l designates an ordinar gear blank mounted `on a shaft 5 which has the usual centering socket 6 in the end thereof.

As is well known, it is desirable to use a degree compass of this character to set oli necessary markings around the outer periph ery of gear blanks such as shown at t, and it not the unusual thing for such work to be extremely diilicult in view. oii' the lack ot an instrument such asset forth herein.

rilhis degree compass preferably consists oif a scale disk 7, around the outer periphery oi which are set oit the degree markings 8. This disk is cut away as shown in Fig. 1 to provide an inner track 9, supported by a series of radially extending spokes 10, which terminate in the center to t'orm a supporting portion 12101' a pointer 13.

Pointer 13 entends radially of disk 7 and is pivotally supported as shown in Fig. 2 by a `tapped rivet 111i which also secures t-wo washers 15 in place on either side ot portion 12. The worl-otacing head ot rivet 1li `is doineshaped to aid in centering the compass when necessary, and a centering pin 16 isscrewthreaded through the tapped opening oil' rivet 1li. This pin 16 may be ot any length, and enters a socketai oit any depth when the device is in use, simply by turning the head of the pin to cause the desired adustment.

To apply the degree compass to work of varying sizes, the disk 7 is provided with a plurality ot brackets, in this instance shown to be three, which are adapted to be entend ed in any suitable manner and to raise and lower the compass from and toward the work.

One form of embodiment ot this part of the invention is shown to be an angled member 17 rigidly secured to one of the spokes 10` by screws or analogous means 18. rlhe outermost end ot member 17 is slidably fitted into the angled portion of an extension ele- `ment 19 which carries a set screw or the like 20 for holding member 17 in the proper po sition with respect to the distance away from gear blank l.

Element 19 supports a set screw 21 which passes through a longitudinal slot 22 formed in the work engaging arin 23. This arm 23, therefore, is movable radially, and may extend for any distance to suit the size `oit the work..

Pivotally mounted pointer 13 carries a set screwor the like Q4 which' is located directly over and engages track 9 when it is desired to secure "the pointer in place. To cooperate wth this set screw 24, a 4rebent lug 9.5 .in-

tegral with pointer 13 engages the outer and` under side of disk 7 in a manner shown in Fig. 2. `When set screw 24 is tightened, pointer 13 cannot be lifted from markings 8 to render the instrument inaccurate.

An extension arm 26 for pointer A13 is provided which is removably snapped into place through the use oi" the well-known ball and detent construction 27 and 28 respectively. This extension is used when the diameter of' the work is greater than that of disk 7, and

(lll

leo

' degree marks maybe scratched on the Work by inserting' any instrument through slot 29 of `the extension 2G or slot 30 of pointer 13. These slots are inradial alinement when the extension is afiixed, andmay also be usedy for sights when desired..

y The operation and application of the degree compass has l been kmade, clear throughout the specification;

`What yI claim and desire to secure by Leti ters l:Patent is:

` Work 'engaging end of l. A degree-compass comprising a'vscale disk 'having degree vmarkings onfthe face thereof around theY outer periphery, a pointer pivota=lly supported at the center of said disk, la'tapped rivet, said pointer being lsupport'edfor rotation "by saidtapped rivet, an adjustable centeringpin in said tapped rivet, theyhe'a'd-of saidrivet adjacent the Y shaped to cooperate therewithin centering said scale disk in the operative position.

lZf-Adegree compass comprisinga scale said pin being dome-` 3. In a degree compass, a scale disk, a

pointer pivotally supported at the center thereof, anda plurality of brackets carried by said disk whereby the same is mounted on Work of varying sizes,l said brackets being extensible radially of said disk and adapted to` be adjusted to move the disk toward and from the work.

In testimony whereof I lwreunto allix my signature.

ARLEIGH COVELL. 

